Stop any dog from barking safely, effectively and humanely! It really works! Barking dog keeping you up at night? Stop it with the Dog Bark Eliminator! Styled after systems developed by veterinarians, this device emits an ultrasonic frequency that"s inaudible to humans, but dogs can"t stand. Simply press a button and it immediately emits a tone to deliver a safe and harmless yet amazingly effective correction. Dog Bark Eliminator also can be used as a coaching device - helps controls dogs that dig through your trash or flower beds! Features expanded 50" range, audible control option, LED flashlight for walking your dog at night and wrist strap. "9V" battery not included. 4-1/4 x 2-1/2 x 1-1/2.